Prossima pubblicazione.
Referenza:
▪ Ertl, A., Henry, D.J., Tillmanns, E. (2018): Tetrahedral substitutions in tourmaline: a review. European Journal of Mineralogy[/i], 30, (in press).
Tetrahedral substitutions in tourmaline: a review
- Marco E. Ciriotti
- Messaggi: 25117
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Tetrahedral substitutions in tourmaline: a review
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 25117
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Tetrahedral substitutions in tourmaline: a review
Referenza:
▪ Ertl, A., Henry, D.J., Tillmanns, E. (2018): Tetrahedral substitutions in tourmaline: a review. European Journal of Mineralogy, 30, (in press).
Abstract:
The Si4+ cation, typically the overwhelming occupant of the tetrahedral site of the tourmaline structure, can be partially replaced by Al3+, B3+, and Be2+. Tetrahedrally coordinated Al (up to ∼0.9 [4]Al atom per formula unit, apfu) has been found in different Mg- and/or Fe2+-rich tourmalines from high-temperature aluminous lithologies as well as in Li-rich pegmatites. It is relatively common for Li- and [4]Al-bearing tourmalines to also contain some [4]B. While the highest boron content (∼0.8 [4]B apfu) in a natural tourmaline was found in an Al-rich tourmaline (olenite) from the Eastern Alps, Austria, much higher contents of up to ∼2.8 apfu have been reported for synthetic Al-rich tourmalines. Natural tourmalines with a higher total Al content (> 7.2 Al apfu) can also contain significant [4]B. The highest verified beryllium content in a tourmaline is still below 100 ppm, but current data show that in pegmatitic tourmaline crystals the Be content is positively correlated with the overall Al content. Therefore Li-rich tourmalines can contain higher Be contents in pegmatites that originated from differentiated granitic magma, than in pegmatites that have evolved as granitic pegmatitic melts from the surrounding country-rocks during decompression.
▪ Ertl, A., Henry, D.J., Tillmanns, E. (2018): Tetrahedral substitutions in tourmaline: a review. European Journal of Mineralogy, 30, (in press).
Abstract:
The Si4+ cation, typically the overwhelming occupant of the tetrahedral site of the tourmaline structure, can be partially replaced by Al3+, B3+, and Be2+. Tetrahedrally coordinated Al (up to ∼0.9 [4]Al atom per formula unit, apfu) has been found in different Mg- and/or Fe2+-rich tourmalines from high-temperature aluminous lithologies as well as in Li-rich pegmatites. It is relatively common for Li- and [4]Al-bearing tourmalines to also contain some [4]B. While the highest boron content (∼0.8 [4]B apfu) in a natural tourmaline was found in an Al-rich tourmaline (olenite) from the Eastern Alps, Austria, much higher contents of up to ∼2.8 apfu have been reported for synthetic Al-rich tourmalines. Natural tourmalines with a higher total Al content (> 7.2 Al apfu) can also contain significant [4]B. The highest verified beryllium content in a tourmaline is still below 100 ppm, but current data show that in pegmatitic tourmaline crystals the Be content is positively correlated with the overall Al content. Therefore Li-rich tourmalines can contain higher Be contents in pegmatites that originated from differentiated granitic magma, than in pegmatites that have evolved as granitic pegmatitic melts from the surrounding country-rocks during decompression.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 25117
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Tetrahedral substitutions in tourmaline: a review
Pubblicazione avvenuta.
Referenza:
▪ Ertl, A., Henry, D.J., Tillmanns, E. (2018): Tetrahedral substitutions in tourmaline: a review. European Journal of Mineralogy, 30, 465-470.
Referenza:
▪ Ertl, A., Henry, D.J., Tillmanns, E. (2018): Tetrahedral substitutions in tourmaline: a review. European Journal of Mineralogy, 30, 465-470.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
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